Shock absorbing apparatus

ABSTRACT

A shock absorbing apparatus that absorbs a shock produced by an abutment of a traveler on a stop member when the traveler is brought to a stop at a predetermined position comprises a leaf spring arranged adjacent to the stop member in substantially face-to-face relationship with a guideway. A free end of the leaf spring abuts slightly on the guideway or with a slight clearance against the guideway. A midportion of the leaf spring is curved gradually apart from the guideway. The traveler is provided with a contact portion that passes over the free end of the leaf spring to contact with the curved midportion before the traveler abuts on the stop member at the predetermined position.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a shock absorbing apparatus for absorbing a mechanical shock that occurs when a traveler running on a guideway is brought to a stop by abutting on a stop member.

[0003] 2. Description of the Prior Art

[0004] A traveler such as a trolley that runs on a guideway is required to be brought to a cushioned stop to convey a load to a predetermined position. It is well known to arrange a resilient member, for example, a rubber or resilient resin pad or a shock absorber to which a traveler is brought engagement resiliently before it abuts on a stop member at the predetermined position.

[0005] However, in the case where the rubber or resilient resin pad is arranged, considerable noise is produced when the traveler brought engagement to the pad. It is also difficult to stop the traveler exactly at the predetermined position because the traveler rebounds from the pad. In the case where the shock absorber is arranged, the noise problem cannot be settled, though the traveler can be brought to an exact stop. The shock absorber comprising a piston and cylinder mechanism, fluid contained in the cylinder and a spring to urge the piston to one end position is expensive and requires large space to be attached.

SUMMARY OF THE INVETON

[0006] It is, therefore, a primary object of the present invention to provide a novel type of a shock absorbing apparatus capable of making a traveler that runs on a guideway stop silently and exactly at a predetermined position.

[0007] Another object of the present invention is to provide a shock absorbing apparatus that is simple in structure and low in cost.

[0008] Further object of the present invention is to provide a shock absorbing apparatus that can be easily disposed adjacent to a stop member on which the traveler abuts at the predetermined position.

[0009] Still another object of the present invention is to provide a shock absorbing apparatus wherein a spring force of a leaf spring urges the traveler to a support surface of the guideway that supports the weight of the traveler when the traveler contacts with the leaf spring. Thereby the traveling speed of the traveler is decreased with keeping the traveler in a stable situation.

[0010] An additional object of the present invention is to provide a shock absorbing apparatus wherein the leaf spring is fixed to the stop member so that the leaf spring is movable therewith when the stop member is moved to alter the predetermined position where the traveler is stopped.

[0011] According to the present invention, the foregoing and other objects are attained by providing within an apparatus which absorbs a shock produced by an abutment of the traveler on the stop member the leaf spring that is arranged adjacent to the stop member in substantially face-to-face relationship with the guideway and comprises a midportion curved gradually apart from the guideway to be contacted by the traveler before the traveler abuts on the stop member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other objects, features and advantages of the invention will be become more apparent from the following description taken in conjunction with the accompanying drawings wherein like references refer to like parts and wherein:

[0013]FIG. 1 is a longitudinal sectional view of a preferred embodiment of the invention;

[0014]FIG. 2 is a section taken along the line 2-2 of FIG. 1; and

[0015]FIG. 3 is a perspective view of a leaf spring.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Referring now to FIG. 1, a shock absorbing apparatus 10 in accordance with the invention is shown which absorbs a mechanical shock that is produced when a traveler such as a trolley 20 movably mounted on a long guideway 30 is brought to a stop by abutting on a stop member 12. As shown in FIG. 2, for the purpose of horizontally securing the guideway 30 at an upper part of a factory there is provided a mount portion 34 on a base 33 of the guideway 30. The guideway 30 has guide portions 35 a, 35 b that extend downwardly in parallel relation with each other on both sides of the base 33. The guide portions 35 a, 35 b are provide with horizontally-inwardly extending support portions 36 a, 36 b on each lower ends to form support surfaces 31 a, 31 b thereon. Rollers 21, 23 rotatably mounted on the trolley 20 are mounted on the support surfaces 31 a, 31 b so that the trolley 20 are guided by the support surfaces 31 a, 31 b of the guideway 30 and the weight of the trolley 20 are taken on the support surfaces 31 a, 31 b. Auxiliary surface 32 is formed on the under surface of the base 33 in face-to-face relationship with said support surfaces 31 a, 31 b. The auxiliary surface 32 abuts with a slight clearance against the summits of the rollers 21, 23 to prevent the rollers 21,23 to move upwardly. Rollers 38, 39 rotatably mounted on respective vertical axes on the trolley 20 are interposed between vertical surfaces 37 a, 37 b formed on the support portions 36 a, 36 b in face-to-face relationship, thereby preventing the trolley from swinging transversely.

[0017] A stop member 12 of the shock absorbing apparatus 10 is interposed between the supporting surfaces 31 a, 31 b and the auxiliary surface 32. The stop member 12 is secured to the guideway 30 by bolting a plate 15 that abuts under surface of the guideway 30 onto the stop member 12 between the vertical surfaces 37 a and 37 b thereby to clasp the support portions 36 a, 36 b between the stop member 12 and the plate 15. A shock absorbing leaf spring 11 is fixed to the front surface 12 a of the stop member 12 at one end, being arranged substantially in face-to-face relationship with auxiliary surface 32 along the guideway 30. The free end of the leaf spring 11 abuts slightly on the auxiliary surface 32, or may abuts with slight clearance against the auxiliary surface 32. The midportion of the leaf spring 11 is curved gradually apart from the auxiliary surface 32. A resilient member 13 is interposed between the stop member 12 and the midportion of the leaf spring 11. The leaf sprig 11 has a flat portion that contacts with the auxiliary surface 32 between the fixed portion to the stop member 12 and the curved midportion. The resilient member 13 is supported between the support surfaces 31 a, 31 b and the flat portion of the leaf spring 11.

[0018] A body 26 of the trolley 20 is constructed of an approximately rectangular plate that has enough thickness to form a body of a construction. The upper portion of the body 26 is disposed between the support surfaces 31 a, 31 b and the auxiliary surface 32, and the lower portion thereof projects below the guideway 20 through the space between vertical surfaces 37 a and 37 b. A front and rear axles 51, 55 are inserted into holes formed transversely horizontally through the upper front and upper rear portions of the body 26 and held thereto by nuts on threaded portions of the axles 51, 55. Front and rear rollers 21, 23 are respectively rotatably mounted on the both end portions of the front and rear axles 51, 55 by means of bearings 52, 56 at both sides of the body 26. Front and rear rollers 21, 23 are respectively mounted on the support surfaces 31 a, 31 b, and the summits of rollers 21, 23 abut with slight clearance against the auxiliary surface 32 so that rollers can run along guideway 20. An auxiliary axle 53 is secured to the body 26 at the upper portion thereof between the front and rear axles 51, 55 in the same manner as axles 51, 55. The auxiliary rollers 22 are rotatably mounted on the both end portions of the auxiliary axle 53 by means of bearings at both sides of the body 26. The auxiliary rollers 22 support the trolley 20 on the support surfaces 31 a, 31 b when the front or rear roller is broken. The front and rear rollers 21, 23 have a same diameter, but the auxiliary rollers 22 have a slightly smaller diameter than rollers 21, 23, thereby being slightly apart from the support surfaces 31 a, 31 b. The auxiliary rollers 22 have higher resistance to rotation than the front and rear rollers 21, 23 to damp the movement of the trolley 20 when the auxiliary rollers 22 make contact with the support surfaces 31 a, 31 b. The rollers 21,23 are made of nylon resin.

[0019] Front and rear rectangular openings 26 a are formed side by side through vertically middle portion of the body 26. Side rollers 38, 39 are respectively disposed in the openings 26 a. A bracket 26 is fixed by bolts 29 on the side of the body 26. Upper and lower tabs bent horizontally from the plane of the bracket 26 are inserted into the openings 26 a to support both ends of vertical axles on which side rollers 38, 39 are rotatably mounted. The side rollers 38, 39 are of a diameter slightly smaller than the distance between vertical surfaces 37 a and 37 b and project beyond respective sides of the body 26, being guided by vertical surfaces 37 a, 37 b to prevent the trolley from swinging transversely while traveling. The body has holes formed through the lower portion thereof to attach a connecting member 40 on which a hook 41 of a hoist is detachably hung.

[0020] The mode of operation of the shock absorbing apparatus will now be briefly described. The hoist is hung on the trolley 20 by hook 41. A load is tied to the hoist to be lifted up from the ground. The trolley 20 is traveled along the guideway 30 to the predetermined position by an operator. Rollers 21, 23 roll on the support surfaces 31 a, 31 b of the guideway 30. If the rollers 21, 23 or axles 51, 55 are broken, auxiliary rollers 22 abut on the support surfaces 31 a, 31 b to prevent the trolley from falling out of the guideway 30. When the trolley is traveled near to the stop member 12, a contact portion 27 on the upper portion of the body 26 contacts with the leaf spring 11 of the shock absorbing apparatus 11 to compress the leaf spring 11 toward the auxiliary surface 32. Leaf spring 11 absorbs the kinetic energy of the trolley 20 to decrease the traveling speed, stopping the trolley 20 exactly at the predetermined position without rebounding when the trolley 20 abuts on the stop member 12. The spring force of the leaf spring 11 urges the traveler 20 to the support surfaces 31 a, 31 b that support the weight of the traveler 20 thereby bringing the traveler 20 a stop in a stable and reliable manner.

[0021] The kinetic energy of the trolley 20 while traveling varies depending upon the weight of a load carried by the trolley. When the weight of a load is changed, the shock absorbing apparatus 10 of the present invention can be easily adjusted to absorb the kinetic energy of the trolley 20 by altering the thickness of the leaf spring 11 to change a spring constant.

[0022] The leaf sprigs may be arranged substantially in face-to-face relationship with support surfaces 31 a, 31 b. The free ends of the leaf springs abuts on the support surfaces 31 a, 31 b, and the midportion of the leaf springs are curved gradually apart from the support surfaces 31 a, 31 b.

[0023] Further, the rollers 21, 23 may be rotatably mounted on the lower front and lower rear portions of the body 26 thereby the trolley 20 is above the support surface on which the rollers roll.

[0024] Still further, shock absorbing leaf spring 11 may be fixed to the base 33 of the guideway 30.

[0025] While particular embodiments of the invention have been described, it will be understood that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is therefore contemplated by the appended claims to cover any such modifications that incorporate those features of these improvements in the true spirit and scope of the invention. 

What is claimed is:
 1. A shock absorbing apparatus which absorbs a shock produced by an abutment of a traveler that runs on a guideway on a stop member when the traveler is brought to a stop at a predetermined position comprising a leaf spring arranged adjacent to a stop member in substantially face-to-face relationship with the guideway; a free end of said leaf spring abutting slightly on said guideway or with a slight clearance against said guideway, a midportion of said leaf spring being curved gradually apart from said guideway, said traveler being provided with a contact portion that passes over said free end of said leaf spring to contact with said curved midportion before said traveler abuts on said stop member at said predetermined position.
 2. An apparatus of claim 1, wherein said guideway comprising a support surface for guiding and taking the weight of said traveler and auxiliary surface disposed in face-to-face relationship with said support surface, said leaf spring being arranged in face-to-face relationship with said auxiliary surface.
 3. An apparatus of claim 1, wherein, said leaf spring being fixed to said stop member at the end opposite said free end, and a resilient member being interposed between said stop member and a midportion of said leaf spring.
 4. An apparatus of claim 2, wherein, said leaf spring being fixed to said stop member at the end opposite said free end, and a resilient member being interposed between said stop member and a midportion of said leaf spring. 